Search results for "Steady-state"
showing 10 items of 29 documents
Remote sensing of solar-induced chlorophyll fluorescence (SIF) in vegetation: 50 years of progress
2019
Remote sensing of solar-induced chlorophyll fluorescence (SIF) is a rapidly advancing front in terrestrial vegetation science, with emerging capability in space-based methodologies and diverse application prospects. Although remote sensing of SIF – especially from space – is seen as a contemporary new specialty for terrestrial plants, it is founded upon a multi-decadal history of research, applications, and sensor developments in active and passive sensing of chlorophyll fluorescence. Current technical capabilities allow SIF to be measured across a range of biological, spatial, and temporal scales. As an optical signal, SIF may be assessed remotely using high-resolution spectral sensors in …
Dynamic Response of a Rigital Displacement Motor Operating with Various Displacement Strategies
2019
Digital displacement technology has the potential of revolutionizing the performance of hydraulic piston pumps and motors. Instead of connecting each cylinder chamber to high and low pressure in conjunction with the shaft position, two electrically-controlled on/off valves are connected to each chamber. This allows for individual cylinder chamber control. Variable displacement can be achieved by using different displacement strategies, like for example the full stroke, partial stroke, or sequential partial stroke displacement strategy. Each displacement strategy has its transient and steady-state characteristics. This paper provides a detailed simulation analysis of the transient and steady…
rbFOX1/MBNL1 competition for CCUG RNA repeats binding contributes to myotonic dystrophy type 1/type 2 differences
2018
Myotonic dystrophy type 1 and type 2 (DM1, DM2) are caused by expansions of CTG and CCTG repeats, respectively. RNAs containing expanded CUG or CCUG repeats interfere with the metabolism of other RNAs through titration of the Muscleblind-like (MBNL) RNA binding proteins. DM2 follows a more favorable clinical course than DM1, suggesting that specific modifiers may modulate DM severity. Here, we report that the rbFOX1 RNA binding protein binds to expanded CCUG RNA repeats, but not to expanded CUG RNA repeats. Interestingly, rbFOX1 competes with MBNL1 for binding to CCUG expanded repeats and overexpression of rbFOX1 partly releases MBNL1 from sequestration within CCUG RNA foci in DM2 muscle ce…
Deciphering function of the pulmonary arterial sphincters in loggerhead sea turtles (Caretta caretta)
2018
To provide new insight to the pathophysiological mechanisms underlying gas emboli (GE) in bycaught loggerhead sea turtles (Caretta caretta), the present study investigated the vasoactive characteristics of the pulmonary and systemic arteries, and the lung parenchyma (LP). Tissues were opportunistically excised from recently dead animals for in vitro studies of vasoactive responses to four different neurotransmitters: acetylcholine (ACh, parasympathetic), serotonin (5HT), epinephrine (Epi, sympathetic) and histamine. The significant amount of smooth muscle in the LP contracted in response to ACh, Epi and histamine. The intrapulmonary and systemic arteries contracted under both parasympatheti…
Kardiale MRT : Änderungen der normalisierten myokardialen Gadolinium-Anreicherung über die Zeit nach Kontrastmittelinjektion in Patienten mit akuter …
2011
PURPOSE An increased normalized gadolinium accumulation (NGA) in the myocardium during early washout has been used for the diagnosis of acute myocarditis (AM). Due to the fact that the pharmacokinetics of contrast agents are complex, time-related changes in NGA after contrast injection are likely. Because knowledge about time-related changes of NGA may improve the diagnostic accuracy of MR, our study aimed to estimate the time course of NGA after contrast injection in patients as well as in healthy volunteers. MATERIALS AND METHODS An ECG-triggered inversion recovery SSFP sequence with incrementally increasing inversion times was repetitively acquired over the 15 minutes after injection of …
Quantitative criteria for the diagnosis of the congenital absence of pericardium by cardiac magnetic resonance
2015
Congenital absence of the left ventricular pericardium (LCAP) is a rare and poorly known cardiac malformation. Cardiac Magnetic Resonance (CMR) is generally used for the diagnosis of LCAP because of its high soft tissue contrast, multiplanarity and cine capability, but the diagnosis is usually made by only qualitative criteria. The aim of the present study was to establish quantitative criteria for the accurate diagnosis of LCAP on CMR.We enrolled nine consecutive patients affected by LCAP (mean age 26±8years, 7 males), 13 healthy controls, 13 patients with dilated cardiomyopathy (DCM), 12 patients with hypertrophic cardiomyopathy (HCM) and 13 patients with right ventricular overload (RVO).…
Assessment of left ventricular function by breath-hold cine MR imaging: Comparison of different steady-state free precession sequences
2005
Purpose To compare steady-state free precession (SSFP) sequence protocols with different acquisition times (TA) and temporal resolutions (tRes) due to the implementation of a view sharing technique called shared phases for the assessment of left ventricular (LV) function by breath-hold cine magnetic resonance (MR) imaging. Materials and Methods End-diastolic and end-systolic volumes (EDV, ESV) were measured in contiguous short-axis slices with a thickness of 8 mm acquired in 10 healthy male volunteers. The following true fast imaging with steady-state precession (TrueFISP) sequence protocols were compared: protocol A) internal standard of reference, segmented: tRes 34.5 msec, TA 18 beats pe…
An Adaptive Robust Predictive Current Control for Three-Phase Grid-Connected Inverters
2011
This paper presents an adaptive robust predictive current control (RPCC) for grid-connected three-phase inverters that exhibit zero steady-state current error. The error correction is achieved by means of an adaptive strategy that works in parallel with the deadbeat algorithm, therefore preserving the typical fast response of the predictive law. The resulting control adapts to any particular L or LCL filter by estimation of the resistive part of the filter. As a variety of the RPCC class of control, it offers the best tradeoff between robustness and speed. © 2009 IEEE.
Steady-state security analysis on the transmission grid for various scenarios of wind generation in Sicily
2009
The proposed paper is part of a research aimed at assessing the impact of wind generation on the transmission grid of Sicily, second among the Italian regions for wind power installed. After describing the current state of wind energy generation in Sicily, the paper reports and comments the results of the steady-state security analysis done for various scenarios of wind penetration. For each scenario (maximum and minimum load conditions), the redistribution of power flows on the transmission network, the voltage profiles at nodes, the analysis of contingencies and losses variations are reported.
Contribution to the platoon distribution analysis in steady-state traffic conditions
2014
The traffic flow analysis and the relevant vehicle distribution (“free-moving” or “platooned” vehicles) on highway facilities at uninterrupted flow has always had fundamental importance in Highway Engineering, with special reference to topics like traffic operations, car accidents, road safety and air pollution emissions. In light of this, the study suggests a calculation algorithm as a random test generator to simulate a steady state traffic flow and to provide time headways. Thanks to the outcome produced by numerical simulations, we analysed platoon distributions within traffic flows in a steady-state regime and showed the results of numerical analyses carried out by traffic random proce…